The field of the disclosure relates to methods and systems for locating visible differences on an object and accurately measuring the locations of potential damage on the object, for example, a large commercial airplane.
Finding and accurately measuring the locations of potential damage on an object, like a large commercial airplane, can be a laborious task. An efficient and automated process for addressing this problem would be valuable to many organizations involved in building and maintaining large vehicles and structures.
From two dimensional images alone it is difficult to get accurate measurements of aircraft locations defined in aircraft coordinates. Often, an item of known dimensions (like a tape measure) is inserted in the picture to give the analyst a size reference. But even with a reference scale, it can be difficult to measure a precise location in the desired coordinate system. Determining the correct location is especially difficult in areas where few uniquely identifiable landmark features exist. In addition, human analysis of a large number of potential damage areas would likely be error prone. Therefore, it is desirable to have as much of the damage detection and location process as automated as possible.
A number of manual or semi-automated options exist to determine local coordinate measurements of damage. One common approach is visual inspection and/or human analysis of images, along with the use of a tape measure to determine damage locations. Using a tape measure can be inaccurate, difficult and somewhat dangerous on an object as large as a commercial airplane, which can involve use of ladders, ropes, scissor or snorkel lifts to reach the damage areas.
The disadvantages of using a tape measure (and similar type of methods) are that the process can be inaccurate, time consuming and includes the possibility of human error. In some situations safety is also a concern, and for measurement of certain objects, contact with measurement tools is undesirable.
A local positioning system (LPS) can be used to provide measurements without climbing on or around the target object (such as an airplane). However, except for the embodiments described herein, the LPS is a manually controlled instrument, which makes the task of finding and measuring a large number of potentially damaged areas very time consuming.